The invention relates to an x-ray diagnostic generator comprising a high voltage transformer with at least one primary winding connected to the mains, and at least one secondary winding which feeds the x-ray tube, as well as comprising a bridge rectifier coupled with the primary circuit of the high voltage transformer to which a capacitor and a thyristor are connected, the thyristor being operated at a frequency and with a pulse duty cycle which correspond to the desired x-ray tube voltage.
An x-ray diagnostic generator of this type is described in the German Offenlegungsschrift No. 2,258,085. In the case of this x-ray diagnostic generator, the adjustment, or regulation, respectively, of the x-ray tube voltage proceeds in the low voltage circuit, on the one hand, so that no high voltage rated components are necessary; and a particularly rapid adaptation (or matching) of the x-ray tube voltage to a desired value takes place, on the other hand. The ripple of the high voltage at the x-ray tube is dependent upon the switching frequency of the thyristor and upon the size of the smoothing (or filter) capacitor. The higher the switching frequency, the lesser the ripple.